I know what you mean but, aside from the excellence of our high speed riding skills, I often wonder whether it is fine rubber particulates being thrown up from the road surface onto a hot cat.
Just watch a heavy truck/Semi taking a tight turn & see how much rubber they leave behind. Something else to worry about, breathing in particulates from the road eh? Diesel soot, tyre debris, metals from sintered brake pads, brake dust generally. There are no cabin air filters to protect us bikers & dust masks aren't exactly de rigueur.